What type of filter is used to filter solutions as the solution is expelled from the syringe?

The use of depth filters in this context is appropriate because they are designed to trap particles within the thickness of the filter media rather than just on the surface, making them effective for filtering solutions that may contain abrasive or particulated matter. As a liquid passes through a depth filter, sediment and particulates get trapped in the structure of the filter, ensuring a more thorough filtration process as the solution is expelled from the syringe.

Depth filters are often used in applications requiring the removal of larger particles or when the solution is viscous, providing greater surface area and depth to retain contaminants effectively. This quality is particularly beneficial in a pharmacy setting, where the purity of injectable solutions is critical.

While membrane filters are also used in many filtration processes, they typically serve a different purpose, focusing on removing microorganisms and are more suited for sterile filtration rather than larger particulates. Intake filters and HEPA filters play specific roles in different environments, such as air filtration or initial liquid intake, but they do not provide the versatile, broad-spectrum filtering capabilities required in this particular scenario where a syringe is being used to expel a solution.